EMS 12 Lead

Calcium Chloride/Gluconate are used during Hyperkalemia induced ECG changes to reduce Serum Potassium.

The answer is: False!

The majority of Potassium in our body is found intracellular. Only a very small percentage (about 2%) is found extracellular, ranging between 3.5- 5.5 mEq/L.

As extracellular Potassium levels increase, the action potential threshold decreases, for example, instead of -90mV, now its -80mV. Remember, the Sodium-Potassium ATPase pump controls these ions, so as Hyperkalemia worsens, the amount of Sodium influx also decreases. All of these factors lead to decreased ventricular conduction, causing shorter QT Intervals, ST-T wave abnormalities and wide QRS complexes on the ECG.

You will not always get the classic “Peaked T” waves or bizarre QRS complex morphologies, but this does not mean that there is no Hyperkalemia, or there is no life threat.

Normal Action Potential (AP) Phases:

In the beginning of the AP (Phase 0), Sodium channels open, with rapid Sodium influx.

While Sodium moves into the cell, a small amount of Potassium exits the cell (Phase 1).

The period where the cell remains inactive is the Resting Membrane Potential (Phase 4).

During Hyperkalemia, a greater amount of Potassium is found extracellular (>5.5mEq/L), altering the resting potential gradient, as Sodium influx is decreased and Potassium influx increases.

The main complication as a result of these electrical disturbances are lethal arrhythmias, which is why Hyperkalemia is so important to suspect. I say suspect, because otherwise, it will go untreated, and untreated means death!

Calcium does not cause intracellular Potassium influx, but it helps maintain the cell membrane AP threshold, the gradient between intracellular Potassium and extracellular Sodium, and vise versa. Because of this, Calcium Chloride or Calcium Gluconate are given along with other medications which increase Potassium influx and excess removal, such as Insulin and Dextrose, Albuterol, Loop diuretics, Sodium Bicarbonate (acidosis) and Kayexalate, often and ultimately, dialysis.

Calcium Chloride 10% has 13.6 mEq/L of elemental calcium per 1g, while 1g of Calcium Gluconate 10% has 4.65 mEq/L, but their effects on cardiac membrane stabilization are equally effective with extremely beneficial results and little to no harm, to the point that many clinicians consider Calcium treatment benign. Treatment leads to ECG normalization, but again, it does not correct the serum Potassium levels.

Be careful with your wording. Diuretics, kayexalate and dialysis do not cause an influx of potassium. In the acute setting, the mainstay of treatments that cause a shift are insulin/glucose, albuterol and, if profoundly acidotic, sodium bicarbonate. The utility of kayexalate is being increasingly questioned and diuretics will not do a thing if your patient is anuric, which is often the case.

Ken Grauer58 Year Old Male, Workout Worry@ Eli — I don’t see AFlutter. That is, I see no indication of regular atrial activity at a rate consistent with AFlutter. Instead, the rhythm is irregularly irregular without P waves = AFib at a controlled ventricular response. In my opinion, one doesn’t need Sgarbossa criteria here to activate the cath lab. So, yes the…
2018-09-13 02:09:24

Vince DiGiulioIs epinephrine harmful in cardiogenic shock?Sorry about that; I copied the quote from the article and my browser automatically changed the "μ" to an "m". Thanks for noticing, and thanks for pointing it out in the most passive-aggressive manner possible.
2018-09-12 16:45:26

Ken Grauer, MDElectrocardiographically Silent High Lateral STEMI EquivalentHi Tom. This is a great case — so NICE that you posted it for others to learned from. But as I commented several times when you sent this case around to our group — the T waves in V2,V3 are disproportionately peaked and transition occurs early (between V1-to-V2) — so the chest leads are NOT…
2018-08-14 08:38:03

Eli58 Year Old Male, Workout WorryAnybody else see the possibility of a LBBB or A-Flutter? I'm not sure if this will make any difference with the treatments but im just trying to interpret it first because if there is a LBBB then it does not meat Sgarbossa criteria and if it is A-Flutter that could explain the hyper acute T's…
2018-07-20 21:29:21